An important factor in the design of hardware, is the provision of adequate cooling of the electronic components employed therein. This is especially the case when designing hardware for use within the modem telecom and datacom industries. In this area it is an absolute requirement that the electronic components that are normally integrated in a cabinet are maintained at normal temperatures. Failure to do so will at least impair the operation and/or functionality of components or even cause them to fail completely.
Additionally, energy consumption during the life cycle of electronic products has the most important environmental and economical impact. Lower energy consumption is a strong sales argument and will be even more important in the future. Energy cost for cooling the electronics during ten-fifteen years is comparable with the unit's purchase price. The ability to keep the temperature of components at the permissible level is a main reason for thermal management. Up until now, telecom cabinets have been successfully cooled by means of forced air cooling, which is a well proven and reliable method that has been used for many years to maintain acceptable temperatures. However, the forced air cooling method suffers from inherent limitations. One such limitation is that the forced air cooling apparatus of today cannot normally handle more than a maximum of approximately 3–5 kW power dissipation per cabinet, depending on the size of the cabinet and/or the power density. In the new generations of telecom and datacom equipment, higher levels of heat flux will make the air cooling methods quite inadequate and will require more efficient cooling solutions. The next generation systems will be further miniaturized, leading to higher power density. Furthermore, they will be higher speed systems with increased power and capacity/performance. All this adds up to increased power dissipation in the form of heat that needs to be handled. Especially for outdoors Radio Base Stations (RBS), other alternative cooling system must be used, e.g. liquid cooling units.
In order to be able to remove heat in the excess of 3–5 kW per cabinet other traditional cooling methods will normally be recommended, such as liquid cooling with or without phase change, thermosyphon or compressor cooling. Thus, it is well known within the art to use traditional compressor cooling systems for cooling air that is in turn used to cool the electronic equipment, such as for in-house telecom and datacom systems. Such electronics cooling systems are in essence based on compressor air-condition systems that are quite expensive and require a great deal of energy, which also is negative from the environmental point of view. Expressed otherwise, the compressor cooling systems have the disadvantage of a low overall coefficient of performance.
Among other frequently used methods of cooling cabinets containing heat dissipating electronic equipment shall be mentioned thermosyphon cooling, having the advantage of requiring no additional energy for its operation. However, today's thermosyphon systems are rather expensive, at least in relation to their limited capacity when it comes to higher heat loads and/or higher ambient temperatures. Further alternatives that are used for cooling equipment containing heat dissipating electronic equipment, such as lasers or magnetic cameras, are i.e. liquid metal cooling and cryogenic cooling.